Optical imaging systems have become an important and ubiquitous tool in tracking many different types of items and machine-vision systems have become an important tool for tasks such as part identification and inspection. Both imaging systems capture a two-dimensional digital image of the optical symbol (in the case of an optical data-reading system) or the part (in the case of a general machine-vision system) and then proceed to analyze that image to extract the information contained in the image. One difficulty that has emerged is that of ensuring that the camera acquires an accurate image of the object; if the camera cannot capture an accurate image of the object, the camera can be unable to decode or analyze the image, or can have difficulty doing so.
One of the difficulties in acquiring an accurate image is ensuring that the object being imaged is properly illuminated. Problems can arise whenever the lighting is of the wrong type or suffers from problems such as non-uniformity. Illuminators exist to provide lighting for optical data-reading systems and machine vision systems, but these have some known shortcomings. Existing illuminators are often round, making them larger than needed and difficult to manufacture. The round shape also makes their lighting pattern a different shape than the field of view of the imager, which can lead to non-uniform lighting, especially near the edges of the image. Other types of existing illuminators can reduce some of these shortcomings, but none overcomes most or all of them.